-ndil

-dil or -ndil is a Quenya suffix added to names to indicate friendship, love, or devotion to an object, idea, grouping, or spirit (Ainur).

Examples:

• Eärendil = "Devoted to the Sea"
• Elendil = "Devoted to the Stars"
• Valandil = "Devoted to the Valar"

References

• The Languages of Tolkien's Middle-earth by Ruth S. Noel
• Quenya Corpus Wordlist edited by Helge Kåre Fauskanger